1. Field of the Invention
The present invention relates to an automatic tool changer for machine tools which are controlled automatically, e.g., NC machine tools.
2. Description of the Prior Art
In this type of known machine tool, an automatic tool changer which, on one hand, takes out from a tool magazine accomodating a large number of tools the desired tool for machining and supplies it to a spindle of the machine tool and which, on the other hand, removes the used tool from the spindle for replacement with the tool required for the next machining operation must be simple in construction and smooth, positive and fast in operation.
To meet these requirements, many different automatic tool changers have been propsed and generally these known automatic tool changer employ the single arm for affecting the demounting and mounting of tools between the spindle and the tool magazine thus giving rise to a disadvantage that the tool changing time is long.